Method of stabilizing organic materials employing pyrazole compounds and stabilized compositions thereof

ABSTRACT

The present invention concerns a novel method of stabilizing organic material susceptible to degradation under the effect of heat, oxidation or ultra-violet light which comprises treating said material with a compound of the formula:   &lt;IMAGE&gt;   WHEREIN R1, R2 and R3 are substituents, e.g. alkyl and Me is hydrogen or a metal cation.

This application is a continuation-in-part of our copending application Ser. No. 485,298, filed July 2, 1974 and now abandoned, which is itself a continuation-in-part of application Ser. No. 447,922, filed Mar. 4, 1974, and now abandoned.

The present invention relates to pyrazole compounds useful as stabilizers against heat, oxidation or ultraviolet light.

Accordingly, the present invention provides a method of stabilizing organic material susceptible to degradation under the effect of heat, oxidation or ultraviolet light which comprises treating said material with a compound of formula I, ##STR2## wherein R₁ is alkyl (C₁ -C₂₂); cycloalkyl (C₅ -C₁₂); cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₇); alkyl (C₁ -C₂₁) thioalkyl (C₁ -C₂₁) with C₂ -C₂₂ in the aggregate thereof; cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₆) thioalkyl (C₁ -C₆) with C₇ -C₁₈ in the aggregate thereof; aralkyl (C₇ -C₁₂); aralkyl (C₇ -C₁₂) substituted on the aryl nucleus by 1 or 2 hydroxyl groups, 1 or 2 alkyl (C₁ -C₁₂) groups, cycloalkyl (C₅ -C₁₂) and/or cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₁₁); phenyl; phenyl substituted by 1 to 3 halogen atoms, cyano, 1 or 2 hydroxyl groups, 1 or 2 alkyl (C₁ -C₁₂) groups, 1 or 2 alkoxy (C₁ -C₁₂) groups, phenyl, --SO₃ H and/or a radical R₄ --O-- or R₄ --SO₂ --, wherein R₄ is phenyl or phenyl substituted by 1 or 2 alkyl (C₁ -C₈) groups;

R₂ has one of the significances of R₁ or is a furan, thiophene, benzothiophene, indole, pyridine or quinoxaline radical, each of which is either unsubstituted or substituted by halogen, alkyl (C₁ -C₄) and/or alkoxy (C₁ -C₄) with 1 or 2 substituents in the aggregate thereof;

R₃ has one of the significances of R₁ or is cyano or --COOR₅,

wherein R₅ is alkyl (C₁ -C₁₂), cycloalkyl (C₅ -C₁₂), cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₇), phenyl or phenyl substituted by hydroxy and/or 1 to 2 alkyl (C₁ -C₈) groups,

and Me is hydrogen or an equivalent of a bivalent metal ion.

A preferred group of compounds in the method of the invention are the compounds of formula Ia, ##STR3## wherein R'₁ and R'₃, are each independently, alkyl (C₁ -C₈), phenyl or phenyl substituted by halogen and/or 1 or 2 alkyl (C₁ -C₄) groups,

Me' is hydrogen or an equivalent of nickel, zinc, manganese, copper, chromium, calcium, barium or cobalt, and

R₂ is as defined above.

A further preferred group of compounds in the method of the invention are the compounds of formula Ib, ##STR4## wherein R'₂ is alkyl (C₆ -C₁₈); cycloalkyl (C₆ -C₈); aralkyl (C₇ -C₁₀); aralkyl substituted on the aryl nucleus by hydroxyl and/or 1 or 2 alkyl (C₁ -C₆) groups; phenyl; phenyl substituted by 1 to 3 halogen atoms, 1 or 2 hydroxyl groups, 1 or 2 alkyl or alkoxy (C₁ -C₈) groups and/or phenyl; a furan, thiophene or benzothiophene radical, unsubstituted or substituted by halogen and/or alkyl (C₁ -C₄), with 1 or 2 substituents in the aggregate thereof, and

R'₁, r'₃ and Me' are as defined above.

A further preferred group of compounds in the method of the invention are the compounds of formula Ic, ##STR5## wherein R"₂ is alkyl (C₈ -C₁₈); cycloalkyl (C₆ -C₈); aralkyl (C₇ -C₁₀); aralkyl substituted on the aryl nucleus by a hydroxyl and/or 1 or 2 alkyl (C₁ -C₆) groups; phenyl; phenyl substituted by 1 or 2 halogen, hydroxyl, 1 or 2 alkyl or alkoxy (C₁ -C₈) groups and/or phenyl with 1 to 3 substituents in the aggregate thereof; or a furan, thiophene or benzothiophene radical unsubstituted or substituted by 1 or 2 halogens or alkyl (C₁ -C₄);

Me" is nickel, zinc, manganese, copper, chromium or cobalt, and

R'₁ and R'₃ are as defined above.

A further preferred group of compounds in the method of the invention are the compounds of formula Id, ##STR6## wherein R"₁ is phenyl, phenyl substituted by alkyl-(C₁ -C₄) or methyl,

R"₃ is alkyl (C₁ -C₄) or phenyl,

R"'₂ is alkyl (C₈ -C₁₁); cyclohexyl; phenylethyl; phenylethyl substituted on the phenyl nucleus by a hydroxyl group, and/or 1 or 2 alkyl (C₁ -C₄) groups; phenyl; phenyl substituted by hydroxyl, 1 or 2 alkyl (C₁ -C₄) groups, alkoxy (C₁ -C₄) and/or phenyl with 1 to 3 substituents in the aggregate thereof; or a furan, thiophene or benzothiophene radical unsubstituted or substituted by chlorine, methyl or ethyl with 1 or 2 substituents in the aggregate thereof,

and

Me" is as defined above.

The invention also provides compounds of formula Ie, ##STR7## wherein R₂ ^(IV) is alkyl (C₈ -C₁₈); a cycloalkyl (C₆ -C₁₂); aralkyl (C₇ -C₁₀); aralkyl substituted on the aryl nucleus by hydroxyl and/or 1 or 2 alkyl (C₁ -C₆) groups; phenyl; phenyl substituted by 1 or 2 halogens, a hydroxyl, 1 or 2 alkyl or alkoxy-(C₁ -C₈) groups and/or phenyl with 1 to 3 substituents in the aggregate thereof and when exclusively substituted by halogen, and Me is hydrogen, then the phenyl has 2 halogen substituents; a furan, thiophene, benzothiophene, indole, pyridine or quinoxaline radical, unsubstituted or substituted by 1 or 2 halogen atoms, 1 or 2 alkyl or alkoxy(C₁ -C₄) groups with 1 or 2 substituents in the aggregate thereof, and

R₁, r₃ and Me are as defined above.

Examples of interesting groups of compounds within the scope of formula I are the compounds of formula If, ##STR8## wherein R₁ ^(V) is alkyl (C₁ -C₆), phenyl or phenyl substituted by alkyl (C₁ -C₄),

R₂ ^(v) is alkyl (C₁ -C₂₀); cyclohexyl; phenyl or phenylethyl, unsubstituted or substituted on the phenyl nucleus by 1 or 2 alkyl (C₁ -C₄) groups, an alkoxy (C₁ -C₄) group, a hydroxyl group and/or a phenyl group and bearing 1 to 3 substituents in the aggregate, a thiophene radical unsubstituted or substituted by an alkyl-(C₁ -C₄) group or chlorine atom, or a quinoxaline radical unsubstituted or disubstituted on the hetero ring thereof by chlorine,

R₃ ^(v) is alkyl (C₁ -C₄) or phenyl and

Me is as defined above, e.g. compounds of formula Ig, ##STR9## wherein R₁ ^(V), R₃ ^(V) and Me are as defined above and

R₂ ^(vi) is alkyl (C₁ -C₂₀), compounds of formula Ih, ##STR10## wherein R₁ ^(V), R₃ ^(V) and Me are as defined above and

R₂ ^(vii) is phenyl or phenylethyl, unsubstituted or substituted on the phenyl nucleus by 1 or 2 alkyl (C₁ -C₄) groups, an alkoxy (C₁ -C₄) group, a hydroxyl group and/or a phenyl group, the compounds of formula Ii, ##STR11## wherein R₁ ^(V), R₃ ^(V) and Me are as defined above and

R₂ ^(viii) is a thiophene radical, unsubstituted or substituted by an alkyl (C₁ -C₄) group or a chlorine atom;

and the compounds of formula Ij, ##STR12## wherein R₁ ^(V), R₃ ^(V) and Me are as defined above and

R₂ ^(ix) is quinoxaline unsubstituted or disubstituted on the hetero ring thereof by chlorine.

Amongst the preferred compounds of formula Ie are the compounds of formula Ie' ##STR13## wherein R₁ ^(VI) is phenyl or phenyl substituted by alkyl (C₁ -C₄),

R₂ ^(x) is alkyl (C₈ -C₁₇), phenyl, phenylethyl or phenyl or phenylethyl substituted on the phenyl nucleus by 1 or 2 alkyl(C₁ -C₄) groups and/or by hydroxyl,

R₃ is alkyl (C₁ -C₄) and

Me^(IV) is H or one equivalent of Ni or Mn.

By the term "halogen" as used herein is meant chlorine and bromine.

Alkyl radicals, unless otherwise stated, are natural or synthesizable primary, secondary or tertiary, straight or branched chain radicals. Examples of primary radicals are methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-undecyl, n-dodecyl, n-hexadecyl, n-heptadecyl, n-octadecyl and n-docosanyl.

Examples of secondary alkyl radicals are isopropyl, 2-butyl, 3-methyl-2-butyl, 2-pentyl, 2-hexyl, 3-hexyl, 2-methyl-3-pentyl, 3-octyl, 4-octyl, 2-decyl, 5-decyl, 2,2-dimethyl-3-octyl, 2-heptadecyl, 2-hexadecyl and 2-nonadecyl.

Examples of tertiary alkyl radicals are tertiary butyl, 3-methyl-3-hexyl, 1-methyl-cyclohexyl and tertiary octyl.

Examples of branched alkyl radicals are 2-methyl-1-propyl, 2,2-dimethyl-1-propyl, 2-methyl-1-butyl, and 2,2-dimethyl-1-decyl.

Examples of cycloalkyl radicals are cyclopentyl, cyclohexyl, cycloheptyl, 2-, 3- or 4-methylcyclohexyl, cyclooctyl and cyclododecyl.

The term "cycloalkyl" as used herein includes a cycloalkyl ring bearing alkyl substituents.

Examples of cycloalkylalkyl are cyclohexylmethyl, cyclohexyl-ethyl and cycloheptyl-methyl.

Examples of aralkyl radicals are benzyl and 2-phenylethyl.

Examples of radicals, where the aliphatic chain is interrupted by sulphur are 2-methylthioethyl, 2-dodecylthioethyl and methyl-thiomethyl.

Examples of substituted phenyl radicals are: ##STR14##

Examples of unsubstituted and substituted furan, thiophene, benzothiophene, indole, pyridine and quinoxaline radicals are: ##STR15##

The present invention also provides a process for producing a compound of formula Ie, which comprises condensing a compound of formula III, ##STR16##

wherein R₁ and R₃ are as defined above, with a compound of formula II,

    r.sub.2.sup.iv cocl                                        II

wherein R₂ ^(IV) is as defined above, preferably in an equimolar ratio and, when Me signifies an equivalent of a metal ion, converting the resulting product into the corresponding Me- salt.

The reaction is preferably effected in an inert organic solvent and the starting materials may be dissolved or suspended therein. The solution is preferably heated to between 20° and 110° C with the cleavage of hydrochloric acid which may be allowed to escape from the reaction vessel at an elevated temperature. Generally, it is, however, more convenient to effect the reaction in the presence of an acid binding agent, e.g. CaO, an alkali metal carbonate or bicarbonate, pyridine, a trialkyl amine or a dialkyl aniline. The reaction is preferably carried out in the absence of moisture. Appropriate solvents are, for example, benzene, xylene, cymol, diphenyl ether, tetrahydrofuran and dioxane. When Me signifies a bivalent metal ion, the compound of formula I, wherein Me signifies hydrogen, may be converted first into the alkali metal salt, e.g. by dissolving the compound of formula I in alcohol and adding an alkali hydroxide such as NaOH or KOH. A Me- salt, e.g. the chloride, is subsequently added to the reaction mixture and the desired product is then obtained.

Alternatively and preferably, a metal salt may be produced directly from the compound of formula I, wherein Me signifies hydrogen, by heating the compound of formula I wherein Me is hydrogen with an Me- acetate, e.g. the acetate of nickel, zinc, manganese, cobalt, copper, calcium or barium. This reaction is preferably effected in an alcohol such as methanol, ethanol and propanol, at a temperature between room temperature and the reflux temperature of the solvent. On cooling the product generally precipitates.

If the product does not precipitate sufficiently, the precipitation may be accelerated by the addition of water.

The compounds of formula I are useful for stabilizing organic material susceptible to degradation under the effect of heat, oxidation or U.V. light by a method comprising treating the organic material with a compound of formula I. By the term "treating" is meant either surface coating or incorporation into the body of the organic material, in manner known per se.

The above method also forms part of the present invention.

The method of the invention comprises treating the organic material, either by way of coating the compound of formula I as a film on the surface of the organic material, or by way of mixing the compound of formula I with the organic material, preferably the latter so as to uniformly distribute the compound of formula I throughout the body of the organic material. Thus, according to a first embodiment the method may be effected by intimately mixing the stabilizer with a particulate form of, for example, a plastics material such as polypropylene, e.g. polypropylene granules, in a kneader or other suitable device, to obtain uniform distribution of the stabilizer throughout the plastics material. The plastics material may thereafter be formed into final shape, e.g. by extrusion or injection moulding. By such method, homogeneous distribution of the stabilizer throughout the plastics material is achieved which is important for good protection.

According to a second embodiment, organic material in final form, for example, a textile filament, is passed through the dispersion of the stabilizer, e.g. in aqueous medium, to provide a protective coating of the stabilizer as a surface film on the organic material. Textile filaments or fabrics of polyethylene terephthalates or cellulose acetate are suited to this mode of application.

According to a third embodiment of the method of the present invention, particularly suited to stabilization of polymers or copolymers, e.g. polypropylene, the stabilizer is mixed with the monomer or prepolymer before polymerisation or, as the case may be, copolymerisation, is effected, to yield the polymer or copolymer having the stabilizer uniformly distributed therethrough. The polymer or copolymer may thereafter be extruded, moulded or otherwise formed into final shape.

Examples of organic materials susceptible to degradation and embraced by the method of the present invention are cellulose derivates, e.g. cellulose acetate, cellulose acetobutyrate, ethyl cellulose, cellulose nitrate and cellulose propionate, polyalkylenes, notably polyethylene and polypropylene, polyvinyl derivatives, e.g. polyvinyl chloride, polyvinyl chloride acetate and polyvinyl alcohol, polyamides, polyesters, polyacrylonitrile, polystyrene, silicon rubber, melamineformaldehyde resins, urea-formaldehyde resins, allyl casting resins, polymethylmethacrylate, polypropylene oxide, polyphenylene oxide polyurethanes, copolymers such as acrylonitrile - butadiene - styrene copolymers and natural products such as natural rubber, cellulose, wool and silk.

The compounds according to the invention are preferably used for the stabilization of polypropylene, polyethylene, polyester, polyamide, polyurethanes, polyacrylonitrile, copolymers such as acrylonitrile-butadiene-styrene (ABS) terpolymer, acrylicester-styrene-acrylonitrile terpolymer, styrene-acrylonitrile copolymer or styrene-butadiene copolymer.

Stabilized organic materials according to the invention may exist in solid form, e.g. panels, rods, coatings, sheets, films, tapes, fibers, granules or powders, or in liquor form, e.g. solutions, emulsions or dispersions.

The amount of stabilizer employed in the method of the present invention will of course vary with the mode of application, the compound employed and the nature of the organic material to be treated. In general, however, satisfactory results are obtained when the amount of stabilizer employed is between 0.01 and 5 %, preferably between 0.05 and 1 % of the weight of organic material to be treated.

The compounds of formula I may be employed in formulation form for the stabilization of organic materials, in association with an inert carrier or diluent. Such formulations may be in the form of polishes, creams and lotions, e.g. for surface application to the organic material so as to form a barrier or filter coating. Such formulations also form part of the present invention.

In the following Examples the parts and percentages are by weight and the temperatures in degrees centigrade. The indicated structures are verified by microanalysis and spectroscopic analysis.

EXAMPLE 1

A mixture of 17.4 parts of 1-phenyl-3-methyl-pyrazolone (5), 11.2 parts of CaO and 19.6 parts of 4-tert.butyl-benzoyl chloride is boiled at reflux in 100 parts of dioxane over the course of 30 minutes. The obtained thick slurry is poured into 200 parts of water, at room temperature and with stirring. The resulting brown solution is acidified with diluted hydrochloric acid, the precipitate is filtered by suction, washed to neutral, dried and crystallized from methanol. The compound of formula ##STR17## is obtained. M.P.: 107°-109° C.

In order to produce the nickel salt, 10 parts of the resulting compound are dissolved in 20 parts of methanol and the stoichiometric amount of nickel acetate is added. The mixture is then heated to 70° C over the course of 30 minutes and allowed to cool. The green precipitate is filtered by suction, washed with methanol/water 1:1 and dried at 110° C. M.P.: 205° C. A practically quantitative yield is obtained. The salts of zinc, manganese, cobalt, copper, calcium or barium are obtained by analogy.

EXAMPLE 2

A mixture of 8.26 parts of 1,3-diphenyl-pyrazolone (5), 3.92 parts of CaO and 9.38 parts of 3,5-di-tert.butyl-4-hydroxybenzoyl chloride is boiled at reflux in 100 parts of dioxane over the course of 2 hours. The mixture is subsequently cooled to room temperature and poured into a solution consisting of 50 parts of 2n hydrochloric acid and 100 parts of ice water. The precipitate is filtered by suction, washed until neutral and crystallized from methanol. The compound of formula ##STR18## is obtained. M.P.: 187°-188° C. The nickel salt may be produced in analogy with Example 1.

EXAMPLE 3

3.75 Parts of 1,3-diphenyl-4[3',5'-di-tert.butyl-4'-hydroxy] benzoyl-5-hydroxy-pyrazole are entered into 60 parts of ethanol and the mixture is heated to 45°. 4 Parts of 2n sodium chloride solution are added at the same temperature. After 10 minutes a solution of 0.94 parts of NiCl₂ -6H₂ O in 20 parts of ethanol is added to the mixture. The solution immediately turns green and KCl is precipitated. After 30 minutes of reaction the KCl is filtered off and the green solution evaporated. The solid residue is washed with water, filtered by suction and dried at 120°. The compound of formula ##STR19## is obtained. M.P.: 250° C.

EXAMPLE 4

34.8 Parts of 1-phenyl-3-methyl-pyrazolone (5) and 13.2 parts of CaO are entered at room temperature into 40.0 parts of dioxane. The mixture is then heated to 80° C in an oil bath. 43.7 Parts of lauric acid chloride are added dropwise at 75° C with stirring. The acid chloride is added over the course of 45 minutes. The temperature is raised to 95° C and a thick, brown well stirrable paste is obtained. After the addition of the acid chloride the mixture is allowed to react at 80° C for 1 hour and is then cooled to 50° C. 100 cc of methanol and 23.0 parts of hydrochloric acid are successively added. After the addition of the hydrochloric acid the mixture is stirred for 30 minutes and 24.8 parts of nickel acetate are added. The mixture is stirred at reflux for 30 minutes (internal temperature: 70° C). The precipitated nickel complex is filtered by suction at 50° C, washed until free from halogen with 1,5 parts of water and then washed twice with 30 parts of methanol each time and dried at 110° C. M.P.: 144°-148° C. The nickel salt of the compound of formula ##STR20## is obtained. The corresponding zinc, cobalt, manganese, copper, calcium or barium complex is produced in analogy with Example 1 or 3.

EXAMPLE 5

A mixture of 53.3 g of 1-phenyl-3-methyl-pyrazolone (5), 18.5 g of CaO and 44.0 g of thiophene-2-carboxylic acid chloride is stirred in 120 cc of dioxane at 95° C over the course of 2 hours. After cooling to 50° C, 100 cc of methanol and 30 cc of concentrated hydrochloric acid are successively added. The mixture is then stirred for a further 30 minutes. The mixture is then poured into 500 cc of ice water, whereupon a voluminous precipitate is obtained. The precipitate is filtered by suction, washed with water and crystallized from methanol. M.P.: 133°-136° C. The compound of formula ##STR21## is obtained.

EXAMPLE 6

A mixture consisting of 20.2 g of 1-phenyl-3-n-propylpyrazolone (5) and 6.2 g of CaO is heated to 75° C in 80 cc of dioxane; 14.7 g of thiophene-2-carboxylic acid chloride are added with stirring at the same temperature over the course of 15 minutes, whereupon the reaction temperature rises to 95° C. The mixture is allowed to react at 95° C for 1 hour and the dioxane is subsequently distilled off. To the resulting thick, brown slurry are added 100 cc of methanol and 10 cc of concentrated hydrochloric acid and the mixture is kept under reflux for 30 minutes. The obtained clear, brown solution is poured on 200 cc of ice water. The reaction product precipitates. The precipitate is filtered by suction, washed with water and crystallized from ethanol. M.P.: 124°-128° C. The compound of formula ##STR22## is obtained.

EXAMPLE 7

5.0 g. of Nickel acetate 6H₂ O are added at 45° C to 12.5 g of the compound of Example 6 in 100 cc of methanol. The mixture is stirred for 1 hour without further heating. The green precipitate is filtered by suction, washed with water and dried at 90° C. M.P.: 145°-155° C. The compound of formula ##STR23## is obtained.

EXAMPLE 8

To 18.8 g of 1-p-tolyl-3-methyl-pyrazolone (5) and 6.18 g of CaO in 100 cc of dioxane there are added with stirring at 90° C over the course of 30 minutes 14.7 g of thiophene-2-carboxylic acid chloride. The dioxane is subsequently distilled off in a water-jet vacuum. 80 cc of methanol and 10 cc of concentrated hydrochloric acid are added at 60° C to the resulting thick paste which is boiled under reflux over the course of 30 minutes. 11.8 g of Nickel acetate 6H₂ O are then added, the mixture is stirred for a further 30 minutes and subsequently cooled to room temperature. The green precipitate is filtered by suction, washed with water and dried. M.P.: 180°-184° C. The compound of formula ##STR24## is obtained.

EXAMPLE 9

A solution of 1.6 g of NaOH in 10 cc of water is added at 45° C to 11.4 g of the compound of Example 5 in 100 cc of methanol and the mixture is stirred for 30 minutes. 4.6 g of NiCl₂.6H₂ O, dissolved in 20 cc of water, are then added to the yellow solution. After the addition of the nickel chloride a green precipitate is obtained which is filtered by suction at room temperature, washed with water and dried. M.P.: 175°-180° C. The compound of formula ##STR25## is obtained.

EXAMPLE 10

5.0 g of Cobalt (II) acetate are added with stirring at 45° C to 11.4 g of the compound of Example 5 in 150 cc of methanol. After the addition of the salt a precipitate is obtained. The yellow precipitate is filtered by suction at room temperature, washed with water and dried. M.P.: 165°-170° C. The compound of formula ##STR26## is obtained.

The compounds indicated in Tables 1, 2, 3 and 4 are produced in analogous manner to that described in Examples 1 to 10.

                  Table 1                                                          ______________________________________                                          ##STR27##                                                                     Ex.                                                                            No.  R.sub.1     R.sub.3  R.sub.2                                              ______________________________________                                         11                                                                                   ##STR28##  CH.sub.3                                                                                 ##STR29##                                           12                                                                                   ##STR30##  CH.sub.3                                                                                 ##STR31##                                           13                                                                                   ##STR32##  CH.sub.3                                                                                 ##STR33##                                           14                                                                                   ##STR34##  CH.sub.3                                                                                 ##STR35##                                           15                                                                                   ##STR36##  CH.sub.3                                                                                 ##STR37##                                           16                                                                                   ##STR38##  CH.sub.3 C.sub.8 H.sub.17 (n)                                 17                                                                                   ##STR39##  CH.sub.3 C.sub.17 H.sub.35 (n)                                18                                                                                   ##STR40##  CH.sub.3                                                                                 ##STR41##                                           19                                                                                   ##STR42##                                                                                  ##STR43##                                                                               ##STR44##                                           20                                                                                   ##STR45##                                                                                  ##STR46##                                                                               ##STR47##                                           21                                                                                   ##STR48##                                                                                  ##STR49##                                                                              C.sub.8 H.sub.17 (n)                                 22                                                                                   ##STR50##                                                                                  ##STR51##                                                                               ##STR52##                                           23                                                                                   ##STR53##                                                                                  ##STR54##                                                                              n-C.sub. 11 H.sub.23                                 24   CH.sub.3    CH.sub.3                                                                                 ##STR55##                                           25                                                                                   ##STR56##  CH.sub.3                                                                                 ##STR57##                                           26                                                                                   ##STR58##  CH.sub.3                                                                                 ##STR59##                                           27                                                                                   ##STR60##  C.sub.3 H.sub.7 -n                                                                       ##STR61##                                           ______________________________________                                    

                  Table 2                                                          ______________________________________                                          ##STR62##                                                                     Ex.                                                                            No.    R.sub.3  R.sub.2             Me                                         ______________________________________                                         28     CH.sub.3                                                                                 ##STR63##          Ca                                         29     CH.sub.3                                                                                 ##STR64##          Ni                                         30     CH.sub.3                                                                                 ##STR65##          Mn                                         31     CH.sub.3                                                                                 ##STR66##          Cu                                         32     CH.sub.3                                                                                 ##STR67##          Ca                                         33     CH.sub.3                                                                                 ##STR68##          Ni                                         34     CH.sub.3                                                                                 ##STR69##          Cu                                         35     CH.sub.3                                                                                 ##STR70##          Ni                                         36     CH.sub.3                                                                                 ##STR71##          Cu                                         37     CH.sub.3                                                                                 ##STR72##          Mn                                         38     CH.sub.3 C.sub.8 H.sub.17 (n)                                                                               Ni                                         39     CH.sub.3                                                                                 ##STR73##          Ni                                         40     CH.sub.3                                                                                 ##STR74##          Cu                                         41     CH.sub.3                                                                                 ##STR75##          Zn                                         42     CH.sub.3                                                                                 ##STR76##          Ni                                         43     CH.sub.3                                                                                 ##STR77##          Mn                                         44     CH.sub.3                                                                                 ##STR78##          Mn                                         45     CH.sub.3                                                                                 ##STR79##          Zn                                         46     CH.sub.3                                                                                 ##STR80##          Ni                                         47     CH.sub.3                                                                                 ##STR81##          Ni                                         48     nC.sub.3 H.sub.7                                                                        nC.sub.11 H.sub.23  Ni                                         49     nC.sub.3 H.sub.7                                                                        nC.sub.11 H.sub.23  Mn                                         50     nC.sub.3 H.sub.7                                                                        nC.sub.11 H.sub.23  Zn                                         51     nC.sub.3 H.sub.7                                                                         ##STR82##          Ni                                         52     nC.sub.3 H.sub.7                                                                         ##STR83##          Mn                                         53                                                                                     ##STR84##                                                                              C.sub.8 H.sub.17 (n)                                                                               Ni                                         54                                                                                     ##STR85##                                                                              C.sub.11 H.sub.23 (n)                                                                              Ni                                         55                                                                                     ##STR86##                                                                              nC.sub.11 H.sub.23  Mn                                         56                                                                                     ##STR87##                                                                               ##STR88##          Zn                                         57     "        "                   Mn                                         58     "        "                   Cu                                         59     "                                                                                        ##STR89##          Ni                                         60     "                                                                                        ##STR90##          Mn                                         61     "        "                   Zn                                         62     "                                                                                        ##STR91##          Mn                                         63     "                                                                                        ##STR92##          Ni                                         64     CH.sub.3                                                                                 ##STR93##          Ni                                         65     "        "                   Cr                                         66     "        "                   Zn                                         67     CH.sub.3                                                                                 ##STR94##          Mn                                         68     n-C.sub. 3 H.sub.7                                                                      "                   Ni                                         69     "        "                   Zn                                         70     "        "                   Co                                         71     CH.sub.3 C.sub.13 H.sub.27   Cu                                         72     "        C.sub.13 H.sub.27   Ni                                         73     "        C.sub.15 H.sub.31   Cu                                         74     "        C.sub.15 H.sub.31   Ni                                         75     "        C.sub.17 H.sub.35   Cu                                         76     "        C.sub.17 H.sub.35   Ni                                         ______________________________________                                    

                  Table 3                                                          ______________________________________                                          ##STR95##                                                                     Ex.                                                                            No.   R.sub.1      R.sub.3   R.sub.2                                           ______________________________________                                         77                                                                                    ##STR96##                                                                                   ##STR97##                                                                                ##STR98##                                        78    "            "                                                                                         ##STR99##                                        79    "            "                                                                                         ##STR100##                                       80    "            CH.sub.3                                                                                  ##STR101##                                       81                                                                                    ##STR102##  CH.sub.3  "                                                 82                                                                                    ##STR103##  n-C.sub. 3 H.sub.7                                                                       "                                                 ______________________________________                                    

                  Table 4                                                          ______________________________________                                          ##STR104##                                                                    Ex.                                                                            No.  R.sub.1     R.sub.3  Me   R.sub.2                                         ______________________________________                                         83                                                                                   ##STR105## CH.sub.3 Zn                                                                                   ##STR106##                                     84   "           "        Mn   "                                               85   "           "        Ca   "                                               86   "           "        Cu   "                                               87   "           nC.sub.3 H.sub.7                                                                        Mn   "                                               88   "           "        Zn   "                                               89   "           "        Cr   "                                               90                                                                                   ##STR107## CH.sub.3 Cr   "                                               91   "           "        Mn   "                                               92   "           "        Zn   "                                               93                                                                                   ##STR108##                                                                                 ##STR109##                                                                             Ni                                                                                   ##STR110##                                     94                                                                                   ##STR111##                                                                                 ##STR112##                                                                             Mn                                                                                   ##STR113##                                     95   CH.sub.3    CH.sub.3 Ni   "                                               96   CH.sub.3    "        Cr   "                                               97                                                                                   ##STR114## "        Ni                                                                                   ##STR115##                                     98   "           "        Cr   "                                               99   "           "        Mn   "                                               100  "           "        Ni                                                                                   ##STR116##                                     101  "           "        Mn   "                                               102  "           nC.sub.3 H.sub.7                                                                        H    "                                               103  "           "        Ni   "                                               104  "           "        Mn   "                                               105                                                                                  ##STR117## CH.sub.3 Ni                                                                                   ##STR118##                                     106  "           "        Zn   "                                               107                                                                                  ##STR119## CH.sub.3 Ni                                                                                   ##STR120##                                     108  "           "        Zn   "                                               109  "           "        Mn   "                                               110                                                                                  ##STR121## "        Ni   "                                               111  "           "        Zn   "                                               112  CH.sub.3    CH.sub.3 Ni                                                                                   ##STR122##                                     113                                                                                  ##STR123## CH.sub.3 Ni                                                                                   ##STR124##                                     114  "           "        Zn   "                                               115  "           "        Co   "                                               ______________________________________                                    

EXAMPLE 116

34.8 parts of 1-phenyl-3-methyl-pyrazolone (5) and 13.2 parts of CaO are entered into 40.0 parts of dioxan at room temperature. The mixture is then heated in an oil bath to 80° C. At 75° C, 38.0 parts of capric acid chloride is added dropwise with stirring over a period of 45 minutes. The temperature increases to 95° C to result in a thick brown, well-stirrable paste. After the addition of the acid chloride, the mixture is allowed to further react at 80° C for 1 hour. The mixture is then cooled to 50° C, 100 ml of methanol and 23.0 parts of hydrochloric acid are added thereto and the mixture is stirred for 30 minutes. 24.8 parts of nickel acetate are then transferred to the mixture and stirring is effected for 30 minutes at 70° C. The precipitated nickel complex is filtered off at 50° C, washed with 1.5 parts by weight of distilled water, washed twice with 30 part amounts of methanol and dried at 110° C. When the above procedure is followed, a product is obtained having between 0 and 2 mols of water of crystallisation and being in accord with the following formula ##STR125## Melting point 158°-162° C.

METHOD EXAMPLE

5 samples of unstabilized polypropylene and 0.5 % by weight, of the compound of Examples numbers 25, 28, 43, 52 and Table 2 and of the compound of Example 9, respectively, are intimately kneaded on a roll mill at 180°. Each sample is extruded into sheets of 0.3 mm thickness. Specimens of the sheets were tested for stability in the "Klimatest" apparatus by the De La Rue method at 40° and 75 % relative atmospheric humidity, with thorough ventilation and irradiation by 16 sun lamps and 16 black lamps of Philips manufacture. Specimens of an unstabilized polyvinyl chloride sheet and a sheet containing 0.5 % of the compound of Example 17 in Table 1 were tested in analogous manner in the "Klimatest" apparatus.

Analogous results are obtained for polyethylene, acrylonitrile-butadiene-styrene terpolymers, polyethylene terephthalate, cellulose acetobutyrate, polyamide 6, polystyrene, polycarbonate and polyurethane. 

What is claimed is:
 1. A method of stabilizing a natural or synthetic polymeric material susceptible to degradation under the effect of heat, oxidation or ultra-violet light which comprises treating said material with a stabilizing effective amount of a compound of the formula: ##STR126## wherein R₁ is alkyl (C₁ -C₂₂); cycloalkyl (C₅ -C₁₂); cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₇); alkyl (C₁ -C₂₁) thioalkyl (C₁ -C₂₁) with C₂ -C₂₂ in the aggregate thereof; cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₆) thioalkyl(C₁ -C₆) with C₇ -C₁₈ in the aggregate thereof; aralkyl (C₇ -C₁₂); aralkyl (C₇ -C₁₂) substituted on the aryl nucleus by 1 or 2 hydroxyl groups, 1 or 2 alkyl (C₁ -C₁₂) groups, cycloalkyl (C₅ -C₁₂) and/or cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₁₁); phenyl; phenyl substituted by 1 to 3 halogen atoms, cyano, 1 or 2 hydroxyl groups, 1 or 2 alkyl (C₁ -C₁₂) groups, 1 or 2 alkoxy (C₁ -C₁₂) groups, phenyl, --SO₃ H and/or a radical R₄ --O-- or R₄ --SO₂ --,wherein R₄ is phenyl or phenyl substituted by 1 or 2 alkyl (C₁ -C₈) groups; R₂ has one of the significances of R₁ or is a furan, thiophene, benzothiophene, indole, pyridine or quinoxaline radical, each of which is either unsubstituted or substituted by halogen, alkyl (C₁ -C₄) and/or alkoxy (C₁ -C₄) with 1 or 2 substituents in the aggregate thereof; R₃ has one of the significances of R₁ or is cyano or --COOR₅,wherein R₅ is alkyl (C₁ -C₁₂), cycloalkyl-(C₅ -C₁₂), cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₇), phenyl or phenyl substituted by hydroxy and/or 1 to 2 alkyl (C₁ -C₈) groups, and Me is hydrogen or an equivalent of a bivalent metal ion.
 2. A method according to claim 1, wherein said material is treated with a compound of the formula: ##STR127## wherein R₁ ' and R₃ ', are each independently, alkyl (C₁ -C₈), phenyl or phenyl substituted by halogen and/or 1 or 2 alkyl (C₁ -C₄) groups,Me' is hydrogen or an equivalent of nickel, zinc, manganese, copper, chromium, calcium, barium or cobalt, and R₂ is as defined in claim
 1. 3. A method according to claim 2, wherein said material is treated with a compound of the formula: ##STR128## wherein R₂ ' is alkyl (C₆ -C₁₈); cycloalkyl (C₆ -C₈); aralkyl (C₇ -C₁₀); aralkyl substituted on the aryl nucleus by hydroxyl and/or 1 or 2 alkyl (C₁ -C₆) groups; phenyl; phenyl substituted by 1 to 3 halogen atoms, 1 or 2 hydroxyl groups, 1 or 2 alkyl or alkoxy (C₁ -C₈) groups and/or phenyl; a furan, thiophene or benzothiophene radical, unsubstituted or substituted by halogen and/or alkyl (C₁ -C₄), with 1 or 2 substituents in the aggregate thereof, andR₁ ', r₃ ' and Me' are as defined in claim
 2. 4. A method according to claim 3, wherein said material is treated with a compound of the formula: ##STR129## wherein R₂ " is alkyl (C₈ -C₁₈); cycloalkyl (C₆ -C₈); aralkyl (C₇ -C₁₀); aralkyl substituted on the aryl nucleus by a hydroxyl and/or 1 or 2 alkyl (C₁ -C₆) groups; phenyl; phenyl substituted by 1 or 2 halogen, hydroxyl, 1 or 2 alkyl or alkoxy (C₁ -C₈) groups and/or phenyl with 1 to 3 substituents in the aggregate thereof; or a furan, thiophene or benzothiophene radical unsubstituted or substituted by 1 or 2 halogens or alkyl (C₁ -C₄);Me" is nickel, zinc, manganese, copper, chromium or cobalt, and R₁ ' and R₃ ' are as defined in claim
 2. 5. A method according to claim 4, wherein said material is treated with a compound of formula Id, ##STR130## wherein R₁ " is phenyl, phenyl substituted by alkyl-(C₁ -C₄) or methyl,R₃ " is alkyl (C₁ -C₄) or phenyl, R₂ "' is alkyl (C₈ -C₁₁); cyclohexyl; phenylethyl; phenylethyl substituted on the phenyl nucleus by a hydroxyl group, and/or 1 or 2 alkyl (C₁ -C₄) groups; phenyl; phenyl substituted by hydroxyl, 1 or 2 alkyl (C₁ -C₄) groups, alkoxy (C₁ -C₄) and/or phenyl with 1 to 3 substituents in the aggregate thereof; or a furan, thiophene or benzothiophene radical unsubstituted or substituted by chlorine, methyl or ethyl with 1 or 2 substituents in the aggregate thereof,and Me" is as defined in claim
 4. 6. A method according to claim 1, wherein said material is treated with a compound of the formula: ##STR131## wherein R₂ ^(IV) is alkyl (C₈ -C₁₈); a cycloalkyl (C₆ -C₁₂); aralkyl (C₇ -C₁₀); aralkyl substituted on the aryl nucleus by hydroxyl and/or 1 or 2 alkyl (C₁ -C₆) groups; phenyl; phenyl substituted by 1 or 2 halogens, a hydroxyl, 1 or 2 alkyl or alkoxy-(C.sub. 1 -C₈) groups and/or phenyl with 1 to 3 substituents in the aggregate thereof and when exclusively substituted by halogen, and Me is hydrogen, then the phenyl has 2 halogen substituents: a indole, pyridine or quinoxaline radical, unsubstituted or substituted by 1 or 2 halogen atoms, 1 or 2 alkyl or alkoxy-(C₁ -C₄) groups with 1 or 2 substituents in the aggregate thereof, andR₁, r₃ and Me are as defined in claim
 1. 7. A method according to claim 6, wherein said material is treated with a compound of formula Ie', ##STR132## wherein R₁ ^(VI) is phenyl or phenyl substituted by alkyl (C₁ -C₄),R₂ ^(x) is alkyl (C₈ -C₁₇), phenyl, phenylethyl or phenyl or phenylethyl substituted on the phenyl nucleus by 1 or 2 alkyl-(C₁ -C₄) groups and/or by hydroxyl, R₃ is alkyl (C₁ -C₄) and Me^(IV) is H or one equivalent of Ni or Mn.
 8. A method according to claim 1, wherein said material is treated with a compound of formula If, ##STR133## wherein R₁ ^(V) is alkyl (C₁ -C₆), phenyl or phenyl substituted by alkyl (C₁ -C₄),R₂ ^(v) is alkyl (C₁ -C₂₀); cyclohexyl; phenyl or phenylethyl, unsubstituted or substituted on the phenyl nucleus by 1 or 2 alkyl (C₁ -C₄) groups, an alkoxy (C₁ -C₄) group, a hydroxyl group and/or a phenyl group and bearing 1 to 3 substituents in the aggregate, a thiophene radical unsubstituted or substituted by an alkyl-(C₁ -C₄) group or chlorine atom, or a quinoxaline radical unsubstituted or disubstituted on the hetero ring thereof by chlorine, R₃ ^(v) is alkyl (C₁ -C₄) or phenyl and Me is as defined in claim
 1. 9. A method according to claim 8, wherein said material is treated with a compound of the formula: ##STR134## wherein R₁ ^(V), R₃ ^(V) and Me are as defined in claim 8, andR₂ ^(vi) is alkyl (C₁ -C 20).
 10. A method according to claim 8, wherein said material is treated with a compound of the formula: ##STR135## wherein R₁ ^(V), R₃ ^(V) and Me are as defined in claim 8, andR₂ ^(vii) is phenyl or phenylethyl, unsubstituted or substituted on the phenyl nucleus by 1 or 2 alkyl (C₁ -C₄) groups, an alkoxy (C₁ -C₄) group, a hydroxyl group and/or a phenyl group.
 11. A method according to claim 8, wherein said material is treated with a compound of the formula: ##STR136## wherein R₁ ^(V), R₃ ^(V) and Me are as defined in claim 8, andR₂ ^(viii) is a thiophene radical, unsubstituted or substituted by an alkyl (C₁ -C₄) group or a chlorine atom.
 12. A method according to claim 8, wherein said material is treated with a compound of the formula: ##STR137## wherein R₁ ^(V), R₃ ^(V) and Me are as defined in claim 8, andR₂ ^(ix) is quinoxaline unsubstituted or disubsubstituted on the hetero ring thereof by chlorine.
 13. A method according to claim 1, wherein the stabilizing compound is incorporated into the body of the polymeric material.
 14. A method according to claim 13, wherein the polymeric material is a plastics material.
 15. A method according to claim 14, wherein the plastics material is selected from polypropylene, polyethylene, polyester, polyamide, polyurethane, polyacrylonitrile, acrylonitrile-butadiene-styrene (ABS) terpolymer, acrylicester-styrene-acrylonitrile terpolymer, styrene-acrylonitrile copolymer and styrene butadiene copolymer.
 16. A stabilized composition comprising a natural or synthetic polymeric material susceptible to degradation under the effect of heat, oxidation or ultra-violet light and incorporated therein, in a sufficient amount to prevent said degradation, a compound of the formula: ##STR138## wherein R₁ is alkyl (C₁ -C₂₂); cycloalkyl (C₅ -C₁₂); cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₇); alkyl (C₁ -C 21) thioalkyl (C₁ -C₂₁) with C₂ -C₂₂ in the aggregate thereof; cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₆) thioalkyl-(C₁ -C₆) with C₇ -C₁₈ in the aggregate thereof; aralkyl (C₇ -C₁₂); aralkyl (C₇ -C₁₂) substituted on the aryl nucleus by 1 or 2 hydroxyl groups, 1 or 2 alkyl (C₁ -C₁₂) groups, cycloalkyl (C₅ -C₁₂) and/or cycloalkyl (C₅ -C₁₁) alkyl (C₁ -C₁₁); phenyl; phenyl substituted by 1 to 3 halogen atoms, cyano, 1 or 2 hydroxyl groups, 1 or 2 alkyl (C₁ -C 12) groups, 1 or 2 alkoxy (C₁ -C₁₂) groups, phenyl, --SO₃ H and/or a radical R₄ --O-- or R₄ --SO₂ --,wherein R₄ is phenyl or phenyl substituted by 1 or 2 alkyl (C₁ -C₈) groups; R₂ has one of the significances of R₁ or is a furan, thiophene, benzothiophene, indole, pyridine or quinoxaline radical, each of which is either unsubstituted or substituted by halogen, alkyl (C₁ 14 C₄) and/or alkoxy (C₁ -C₄) with 1 or 2 substituents in the aggregate thereof; R₃ has one of the significances of R₁ or is cyano or --COOR₅,wherein R₅ is alkyl (C₁ -C₁₂), cycloalkyl-(C₅ -C₁₂), cycloalkyl (C₅ -C₁₁) alkyl(C₁ -C₇), phenyl or phenyl substituted by hydroxy and/or 1 to 2 alkyl (C₁ -C₈) groups,and Me is hydrogen or an equivalent of a bivalent metal ion. 